Magnetic sensors (e.g., linear and variable differential transducers), motors, and actuators (e.g., solenoids) include one or more electromagnetic coils, which are commonly produced utilizing a fine gauge magnet wire; e.g., a magnet wire having a gauge from about 30 to 38 American Wire Gauge. In certain cases, the electromagnetic coils are embedded within a body of dielectric material (e.g., a potting compound) to provide position holding and electrical insulation between neighboring turns of the coils and thereby improve the overall durability and reliability of the coiled-wire device. The opposing ends of a magnet wire may project through the dielectric body to enable electrical connection between an external circuit and the electromagnetic coil embedded within the dielectric body. In many conventional, low temperature applications, the electromagnetic coil is embedded within an organic dielectric material, such as a relatively soft rubber or silicone, that has a certain amount of flexibility, elasticity, or compressibility. As a result, a limited amount of movement of the magnet wire at point at which the wire enters or exits the dielectric body is permitted, which reduces the mechanical stress applied to the magnet wire during assembly of the coiled-wire device. However, in instances wherein the electromagnetic coil is potted within a material or medium that is highly rigid, such as a hard plastic and certain inorganic materials, the magnet wire is effectively fixed or anchored in place at the wire's entry point into or exit point from the dielectric body. As the external segment of the magnet wire is subjected to unavoidable bending, pulling, and twisting forces during assembly, significant mechanical stress concentrations may occur at the wire's entry or exit point from the dielectric body. The fine gauge magnet wire may consequently mechanically fatigue and work harden at this interface during the assembly process. Work hardening of the fine gauge magnet wire may result in breakage of the wire during assembly or the creation of a high resistance “hot spot” within the wire accelerating open circuit failure of the coiled wire device. Such issues are especially problematic when the coiled magnet wire is fabricated from a metal prone to work hardening and mechanical fatigue, such as aluminum.
It would thus be desirable to provide embodiments of an electromagnetic coil assembly including a fine gauge coiled magnet wire, which is at least partly embedded within a body of dielectric material and which is effectively isolated from mechanical stress during manufacture of the coil assembly. Ideally, embodiments of such an electromagnetic coil assembly would provide redundancy in the electrical coupling to the potted coil (or coils) to improve the overall durability and reliability of the electromagnetic coil assembly. It would still further be desirable to provide embodiments of such an electromagnetic coil assembly capable of providing continuous, reliable operation in high temperature applications (e.g., applications characterized by temperatures exceeding 260° C.), such as high temperature avionic applications. Finally, it would be desirable to provide embodiments of a method for manufacturing such an electromagnetic coil assembly. Other desirable features and characteristics of the present invention will become apparent from the subsequent Detailed Description and the appended Claims, taken in conjunction with the accompanying Drawings and the foregoing Background.